Urinary diversion is considered a chronic condition, which affects the lives of patients both physically and psychologically, hence, it is critical to provide those patients with an individualized instruction on self-care, not merely to increase information but to help them adapt successfully to a new life. Self-efficacy is one of the most important known concepts that may help these patients to deal with this situation. Aim: To determine the effect of nursing instructions on self-efficacy among patients with ileal conduit. To fulfill this aim the following research hypothesis was formulated: stoma self-efficacy total scores of patients with ileal conduit who receive nursing instructions will be different from stoma self-efficacy total scores of a control group in the first as well as the second post intervention assessments. Methods: Consecutive nonequivalent pre-test- post-test control group design was utilized to achieve the aim of the study. The study was conducted at Al-kasr Al-Aini University Hospital, Cairo-Egypt. Data was collected using two tools: (a) Personal and Medical Background Information Form and (b) Adapted Stoma Self-Efficacy Scale -Chinese version. Results showed that the participants were predominantly males (78.1% & 87.5%) in both groups. There was a significant difference between the control and the study groups on the variable of overall stoma self-efficacy in the first and second post intervention assessments (P-value= .0001 and .0001, respectively). Most probably these differences are due to the increase in the first and second post intervention mean scores for stoma care self-efficacy (28.6± 0.68 and 31.1±0.69, respectively) and social self-efficacy (17.7± 0.7 and 19.7± 0.69, respectively) among the subjects of the study group than subjects in the control group. Conclusion: There were an improvement in stoma self-efficacy scores along four consecutive weeks for both groups, however, the obvious improvement was in favor of the subjects receiving nursing instructions. Recommendations: a longitudinal study should be designed over a longer period of time to determine the long term effect of nursing instructions on self-efficacy.